


good puppy

by SidewaysClarinet



Category: Shingeki no Kyojin | Attack on Titan
Genre: Biting, Blindfolds, Blood Kink, Catboy Eren Yeager, Creampie, Desperation Play, Dogboy Reiner Braun, Dom/sub, M/M, Marking, Master/Pet, Scratching, Shibari, dont look at me like that ok the art was cute
Language: English
Status: Completed
Published: 2021-02-15
Updated: 2021-02-15
Packaged: 2021-03-16 07:48:25
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,821
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29450292
Author URL: https://archiveofourown.org/users/SidewaysClarinet/pseuds/SidewaysClarinet
Summary: There really should be a manual for training separation anxiety out of your boyfriend; maybe if Eren had one, then they'd be able to make it past the 'giving in and fucking like animals' stage. Reiner certainly isn't complaining, but they can't do this every time, can they?
Relationships: Reiner Braun/Eren Yeager
Comments: 15
Kudos: 186
Collections: Shingeki no Kyojin|Attack on Titan





	good puppy

**Author's Note:**

> what's the point of valentine's day if not enjoying a pretty dogboy getting fucked ????? answer me that liberals

“Stop cowering, Reiner, we haven’t even started.”

Eren blows an errant strand of hair out of his eyes, narrowing them down at the rope between his fingers. He ties a base knot with a quick hand, then picks the ropes up to trace them over Reiner’s shoulders, ignoring the fine trembling of the skin beneath his fingers as he lays the threads flat. Eren gives the pattern a stern look-over, then takes it around to Reiner’s back again, focusing on tying the other man’s wrists together firmly. Once that’s done, he steps back and looks over his handiwork once more.

The knots are solid, and hold tight against Reiner’s anxious wriggling. The solidness of the set up reassures him, and so he steps back further into the room, back towards the chest where their normal toys lay out of sight. There, he retrieves a blindfold and a collar, and he scratches at his ear idly as he returns to Reiner’s side.

“Are you done now?” Eren asks him, raising an eyebrow. 

“I-” Reiner swallows, harshly, turning pleading eyes up to the other man. “Don’t leave me, please.”

Eren doesn’t respond to that at first. He only takes the collar in hand and latches it around Reiner’s neck, letting the heavy weight of the leather and metal fall with an audible sort of ‘thunk’ against his chest. The change is almost instantaneous; Reiner’s eyes widen a bit, and Eren can hear his breath hitch and pick up, surely in anticipation of all the good things that come not long after he’s collared.

“Good boys don’t beg,” Eren tells him. “Good boys do what their masters tell them. Are you going to be a good boy?”

Reiner writhes again, pulling unhappily at the ropes, but neither the thread nor the hardness in Eren’s eyes give way. His ears fall, as do his eyes. “...yes.”

“Yes, what?”

“Y-Yes, sir.”

“There you go.” Eren gives him only one solid pat between the ears, ignoring the way that Reiner attempts to lean into it. He takes the blindfold, then, and wraps it about Reiner’s eyes, tying it securely at the back of his head. The total ensemble is complete, then.

And now Eren really can appreciate his work.

He stands up and steps back, retreating further towards the desk at the corner of their room, and lets himself stare to his heart’s content. Reiner’s face is flushed, all the way down to his neck and across his pale shoulders. The ropes make a stark contrast with his naked skin, and draw in criss-crossing patterns across his chest and abdomen. They squeeze the muscles of his chest and pecs, draw his arms back until they’re straining, and even stretch down to the planes of his abdomen. 

His knees are obediently folded beneath him, and between his hips lies his heavy, untouched and reddened cock, still at full mast despite the shiver that sets across Reiner’s skin. His tail flicks about nervously behind him, and his ears flicker about, trying to find some sort of hint that Eren was still there, that he hadn’t left. It had scarcely been minutes since Eren had left his side, and yet his tail was already starting to curl back towards his hips in that anxious way it always did when he was alone.

But that’s what all of this is about, isn’t it? Reiner was too clingy. He couldn’t stand to be away from Eren for too long, and would whine and complain all day until he found his way back to Eren’s side. It doesn’t bother him, really; Reiner is calmer at his side, anyways, and he’s typically quiet, content to do his own thing so long as Eren is close by. The only catch is, well… it stokes a dark part of Eren, every time he sees the other man shiver and search about for him, eyes wide and desperate. This is just the culmination of that.

He wants to see how desperate Reiner really can get. That, and how long he himself can last without fucking those delicious little whimpers out of him.

 _He’s too damn cute for his own good,_ Eren thinks to himself. His tail flicks beside him, reflective of his curiousness, and he quickly snatches it up. Can’t give Reiner any sound to go off of, after all. He smooths down his fur instead, preening at it idly as he turns his eyes back up to Reiner.

The other man’s mouth has parted, now, as soft, quick breaths fall across his lips. His squirming is more pronounced now, and probably has as much to do with the straining of his erection as it does with the lack of knowing where Eren is. He sees Reiner’s nose twitch, but still itself quickly—that’s good, then, it means he’s still following the rules. Eren nods approvingly to himself. _Good puppy._

It’s another few minutes, longer than Eren had initially expected, before Reiner’s tail starts to move again, curling between his legs as his ears flatten down. The first whine comes out; it’s a quiet, muted one, and it spurs Eren into motion. The sound is addicting, really, and he wants more of it.

He slinks silently across the floor, coming up behind Reiner to draw a light hand across the skin of his shoulders. Reiner flinches almost violently, and leans back into his touch just as quickly afterwards, but Eren is already pulling away and out of range. Reiner whines louder then, shifting to and fro. It makes Eren grin, safely out of the other man’s sight. Next is a soft touch through his hair, and another skating brush of Eren’s fingers against his jaws. The trembling grows more pronounced, as does the redness of his cock.

“Eren,” Reiner breathes, voice pitched and pleading already. “Eren, Eren-”

“Shut up,” he says, tonelessly. “I didn’t say you could speak. You don’t want to be punished, do you?”

Reiner’s mouth snaps shut audibly, and he shrinks back, falling quiet as he’s been told. Eren smiles, leaning down to put his mouth close to the other man’s furry ear.

“That’s a good boy,” he murmurs, watching the flush on Reiner’s face deepen. 

He doesn’t linger, doesn’t stay in one place. One moment, he might be ghosting across Reiner’s skin, tracing fingers across pale skin or over raised scars. The other moment, he might draw back completely, leaving Reiner alone in their cold room. Each touch ramps him up, has him tensing and relaxing, has the soft whimpers he tries to hide growing in pitch and volume. 

He whines openly now, tail trembling and mouth open with his hot, heavy breaths. He’s lasted longer than Eren had expected before, but still hardly very long at all; he supposes he’ll just have to train the patience into his disobedient little puppy.

“Eren,” he finally pleads. His voice is pitiful, and almost pathetic in a cute sort of way. “Please, come back, I miss you. Please?”

Eren scoffs, leaning out of Reiner’s reach again. Truth be told, his pants are straining with the ferocity of his erection, and he wants nothing more than to bend Reiner over already. But, he does have a role to play. “So soon? You’re pathetic, you know. Acting like you’ve earned anything when you’ve barely been following the rules. You don’t deserve it.”

“I know, I know,” Reiner whimpers. “Please, I’m sorry, please? I- I don’t want to play anymore-”

“Already, huh?” Eren gives a click of his tongue, ignoring the other man’s wordless pleas and begging. He steps closer, but as soon as he’s close, Reiner suddenly doubles over. Eren blinks, surprised as Reiner presses his face to his boots, nuzzling into his ankles and shuffling closer. “...what are you doing?”

Reiner’s voice is wet with tears. “Touch me, please? I need you, I need you.”

 _Well, when he puts it like that._ Eren feels something in his chest give—he’s an asshole, sure, but not cruel. He steps away from Reiner and kneels down, catching the other man by the hair and dragging him up before he can start begging again. Reiner’s already crowding into his space, pressing against him, trying to get any point of contact and mostly succeeding. He’s so desperate that it startles Eren, and honestly, turns him on a whole hell of a lot more than he thought it would.

“You’re so hopeless,” he says, a bit of affection coloring his voice as Reiner’s ears flicker against his wrist, pulling close and yet flinching away from the tight grip in the strands of his hair. “Maybe I should just tie you up and lock you in another room for a day, huh? How’s that? I won’t even be there for you to bootlick and suck up to.”

Reiner doesn’t even respond to that, too busy trying to buck up into Eren’s hand for some sort of contact. The blindfold around his eyes is already wet enough with tears that they’re starting to slip free. Eren tightens his grip, forcing him backwards and away. 

“Are you listening to me?” Eren asks. “I’m going to lock you up and leave you alone. I’ll probably throw away the key and leave you forever.”

He can’t see Reiner’s eyes beneath the blindfold, but Eren can see his mouth, the way it falls open, and his brows, the way they twist and raise in distress. “No, please, Eren- master, please?”

“Oh.” Eren’s breath leaves him in a quick, amazed little huff. “How am I supposed to be kind to you when you’re so pretty all riled up? All I want is to be cruel to you.”

“It’s fine,” Reiner breathes, getting as far into Eren’s lap as he can. “I don’t mind, just let me stay with you, whatever you want, just let me stay.”

Eren finally releases the grip on Reiner’s hair, and the other man topples forward a bit. Eren takes his face in hand, cradling it gently and leaning close to press their foreheads together. It’s almost ungodly, how affectionate he feels for his puppy. 

“You shouldn’t say things like that,” he murmurs. “I’ll take you up on it, and you’ll end up regretting it. You know I love taking you apart.”

Reiner shivers, and it has to speak measures about how fucked up he is, too, to get so excited about the truly terrible things Eren wants to do to him. “...it’s fine, I want it.”

“As long as I’m with you?” Eren asks, eyebrow raised. Reiner gives a nod, leaning his head to the side to press kisses to Eren’s wrist. “What if I kept you on my cock for a whole day? If I teased you until you begged me to touch you, to fuck you? Or I could keep you in a cage like the mutt you are, leashed up and tied down. I bet I could even feed you in a bowl and you’d be happy, wouldn’t you?”

To his amusement, Reiner’s cock twitches, and he rubs his thighs together, desperate for touch but knowing better than to interrupt. Eren gives a wicked sort of grin, leaning in to the other man’s exposed neck to kiss at the skin just beneath his ear. Reiner stills in his hold, only moving to expose more of his neck as Eren lays another kiss down, flicking his tongue out to savor the taste of Reiner’s skin, baring his teeth to bite down and taste the pretty iron that pearls up from the broken skin. He licks up the stray droplets of blood, and instead sucks more dark marks into Reiner’s neck, loving the soft little moans that his ministrations draw forth.

It isn’t long until that isn’t enough; it’s like every time he gets a taste of Reiner, he just wants more. He wants to selfishly hoard every moan and whine, the flavor of his skin, the stain of his blood. He wants everything, everything that Reiner will give him—and Reiner is willing to give so, so much. It gives him a feeling like a high, the power it gives him.

Eren’s gentle grip on Reiner’s face has long since grown bruising, and he takes his hands away, instead grabbing on to the other man’s shoulders and digging his claws in until Reiner gasps out.

“Bend over,” Eren murmurs into his neck, hungry and demanding. “On your knees. Now.”

He can feel the goosebumps that raise on Reiner’s flesh at the command. His eager puppy is ever-happy to obey, and as Eren leans back to give him room, he gets himself into position wordlessly. He doesn’t even hesitate when it’s obvious that his tied-up hands won’t allow him to hold himself up; he only leans his cheek on the floor, ass up, tail nervously keeping himself covered and yet his body is waiting and pleading, surrendering. Eren can barely keep control of himself.

It’s in a blur that he finds the bottle of lube and gets his buckle undone, yanking his pants down and barely caring when the fabric pulls at the fine fur of his tail. His eyes are on Reiner’s ass, and his anxiously curling toes, his thighs that rub together in anticipation, his flushed face and where stray tears escape from the dark fabric of the blindfold. Eren wets his fingers with the lubricant, but doesn’t wait for it to get warm; Reiner’s soft gasp when it hits his entrance makes it worth it.

Reiner’s tail brushes over his hand as he works a finger in. With a scowl, Eren snatches it up in his free hand and pulls it away, drawing a whimper and a flinch. He holds it back, focusing his attention on getting that finger further in, curling and thrusting it in, before adding in a second. Reiner makes a noise, twitching and squirming as the two fingers stretch him open impatiently, torn between bucking back into the penetration or pulling away from it. 

His mouth falls open at the third finger, and Eren screws it in deeper, avoiding that part that’ll make Reiner see stars because it’s not time yet, that mutt of his better not even dare trying to get off to this before Eren has given him permission. The fact that he’s already panting is worthy of punishment enough; who the fuck told him to let it feel good?

Eren doesn’t take any longer than necessary to prep him. Like always, Reiner had snapped his patience, and now all Eren wants is to ruin him, to tear him up from the inside and the outside, to sate the part of himself that wants Reiner’s blood and tears. He knows the other man wants it, too; if not because of previous discussion and planning, then because of the deep flush across his back, the way he bucks into Eren’s fingers, the way he shivers and pleads with Eren that, _‘please, please, I’m ready, I want you, do it now-’_

His hand is rough, coarse, when it coats his own waiting cock with more lube. The touch sends curling warmth down his skin, makes him eager to do more, take more. One hand goes to Reiner’s hips to hold him still, and the other to the arch of Reiner’s back, to push him down, pull his hips up, manhandle him the way that Eren likes. Then, he’s pushing in, sinking inch after inch into Reiner’s waiting warmth in a way that makes the other man gasp out, chest heaving, ears bright red and arms trembling against the hold of the ropes.

And it’s here that he pauses, that he waits. He waits because he can feel every inch of Reiner’s walls clamping down on him, and he knows that the other man feels it, too. He knows this because of the way Reiner’s tail flicks about in his hand, and the way that the trembling of his body starts to turn more pronounced, more desperate with every pitiful while that falls from his mouth.

“Fuck me, please?” he asks, begs, in the way that Eren knows he will when he waits just long enough. “I need you.”

“Say it, then,” Eren tells him, keeping still.

Reiner’s flush deepens, but he opens his mouth, voice sickly sweet. “Fuck me, master, please.”

And that’s the straw that breaks the camel’s back, isn’t it? It’s like a blade cutting through wire drawn taught, and Eren moves. He snaps his hips forward, drives his cock in so deep that it punches a groan out of Reiner’s chest. He doesn’t let up, then; he keeps a harsh, driving pace, impatient to bruise and fuck the other man in every way he knows how. He digs his fingers into the flesh of Reiner’s hips, grip tight and claws sharp enough to draw blood and breathless moans. 

His other hand rakes his claws down Reiner’s backside, leaving reddened furrows that make the other man gasp and groan. Eren leans over his back, licking up the blood and fucking into him like an animal, like a man possessed. 

“Oh God!” Reiner whimpers. His hands scrabble and writhe in their bonds for something, anything to grasp onto, his cheek red where it drags against the floor; Eren tries to sear the sight into his mind. He never wants to forget Reiner’s voice, his flushed face, and the tight, hot warmth around his cock. “Eren, Eren, ah- ngh! Fuck! Please, more!”

“Shut the fuck up,” he hisses, taking one of the ropes in hand and yanking until it draws the other knots tight. “You’ll take what I give you.”

Reiner makes a tortured, keening sort of noise, curling his face into the floor. There’s nothing for him to grasp on to, no way to touch himself, no way to grab on to Eren—all he can do is be good and take it. Not being able to touch himself doesn’t seem to stop him from getting close to cumming; Eren chokes down a grunt at the steadily tightening grip around his cock, where Reiner tenses with each thrust, writhing and squirming and moaning. 

“Fucking whore,” Eren sneers. Reiner’s close already, isn’t he? “Well, go on then. Cum all over yourself. Don’t think it’ll stop me.”

If Reiner is going to cum so soon, then Eren might as well take advantage of his ass while he still has it. He pulls the rope harder, tugging Reiner back and upright until they’re chest-to-back. Reiner’s hands scrabble to grab on to his abdomen uselessly, his mouth falling open, and from here, Eren can see his untouched cock, bouncing against his abdomen as Eren fucks him.

He gets to see the moment when Reiner’s abdomen tenses one last time, gets to hear Reiner’s strangled cry in his ear when he cums. The pressure around Eren’s cock doubles, and he groans, muffling it by biting down onto Reiner’s shoulder. The other man groans weakly, falling limp in his grip, but it works out. Eren shifts his hands, raking his nails across Reiner’s abdomen and digging his claws in for purchase. It takes him another thrust—quick, breathless, and then he’s grunting, burying himself in Reiner’s warmth when he cums.

Reiner, the good boy that he is, rocks his hips shallowly, milking him for all he’s got. Eren stills him with a quiet hiss, too sensitive for the stimulation.

“Lay down,” he tells Reiner, pulling himself free. “On your stomach.”

“Where are you going?” the other man asks him, turning his head so suddenly that he almost knocks into Eren’s nose. Eren frowns, pulling away and pushing Reiner down.

“Don’t be clingy,” he says. He stands up and retreats towards the bathroom, eager to get a washcloth and clean up. “Or we’ll just have to do this all over again.”

“...I wouldn’t mind.” Reiner’s voice is quiet, somewhere between pouting and childish. 

“Yeah, you wouldn’t,” Eren scoffs. He takes up a cloth from the countertop and makes his way back to Reiner who, to his credit, has stayed obediently where Eren told him to. The only movement is the way that his tail starts to wag a bit when he hears Eren approach. “You’re hopeless.”

Contrary to his words, he’s gentle when he wipes Reiner down, washing away cum and sweat and blood alike. He loosens the ropes and pulls them off, easing the reddened marks they leave behind. Even after all of Eren’s work, Reiner is still covered head to toe in bruises, claw marks, and rope burns; it almost makes him want to go for another round, in all honesty.

Almost as an afterthought, he unties Reiner’s blindfold, tossing it aside somewhere for them to pick up later. The other man blinks as he’s suddenly able to see, and the first thing he looks for is Eren—like the dumbass he is, his ears immediately perk up, and his tail flicks again. The collar, he leaves on; Reiner likes it best 

“Hi,” he says, and the fact that it almost sounds _shy_ , even after Eren had fucked the mess out of him, almost makes him snort.

“Go lay down,” Eren replies, instead.

“Will you come with me?”

Eren rolls his eyes. “Will you do what I say already?”

“Yes.”

“Then fine.”

It’s a bluff, really; aftercare is important. He helps Reiner stand, and as the other man retreats into the warm depths of the covers, Eren tosses the dirty cloths in the laundry for later. After a second thought, he strips his own clothes down and throws them out, too. When he turns around, he can see Reiner’s head peeking out from the covers, ears perked with interest.

“What did I say?” Eren demands.

Reiner’s eyes widen, and he pulls the covers tighter around himself. “I’m laying down!”

“Don’t be smart, you know what I meant.” Eren finally makes his way to the bed, and shoos Reiner back from hogging the bed like the douche that he is. He yanks the covers over more fairly, but it hardly gets his point across when Reiner just lunges forward to wrap around him. The other man makes himself Eren’s second skin, cuddling close and nuzzling up beneath his chin. “...Reiner.”

“What?” he asks, peeking up.

“What was I just saying about being clingy?” It’s more for show than anything. Reiner is warm as always, and he’s entirely too comfortable of a cuddle partner. He doesn’t move, and Eren doesn’t either, really.

“I love you,” Reiner murmurs, nosing into his neck. 

_Ah. Cute._

“Suck up,” is what Eren actually says, but it lacks the proper vehemence. It’s a long moment where Reiner is patiently quiet, and Eren tries to resist giving in. He fails. “I love you too, I guess.”

Reiner’s reaction is instantaneous—he wriggles closer, kissing up Eren’s bare shoulder and settling in before finally stilling.

Well, as long as he’s stopped whining so much, then maybe it’s fine.

**Author's Note:**

> i hope you enjoyed <3 follow me on twt @yuri_otoko !
> 
> https://discord.gg/KMsfae9e6H << feel free to join my discord server for aot introverts!


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